The present invention relates generally to agricultural mower-conditioners, and more particularly relates to a crop header in which the conditioning apparatus is configured to improve windrow consistency when used with a rotary disc cutterbar.
Windrower mower-conditioner combinations are well known and typically comprise a cutting mechanism, a conditioning unit, and one or more deflectors to arrange the cut and conditioned crop material into a windrow. The windrower mower-conditioner combination is generally a self-propelled unit, but may also be configured to be propelled by a separate tractor. Typically, a standing crop is cut by a rotating disc cutting mechanism disposed along a leading edge of the combination. The severed crop material is then directed to a conditioner unit that processes the crop for faster drying. The conditioner unit typically comprises a pair of intermeshing rolls that crush the crop material passing therebetween. For background information on the structure and operation of some typical disc mower-conditioners, reference is made to U.S. Pat. No. 5,778,647, issued to McLean et al., the descriptive portions thereof being incorporated herein by reference.
One problem with counter-rotating discs is that crop material tends to be non-uniformly discharged from the cutterbar; crop material tends to be concentrated between converging cutters (ones in which the knife cutting edges approach each other during rotation) leaving a much less dense area in the crop mat between pairs of diverging rotary cutters. Rather than a desirable crop material mat of near-uniform thickness being fed into the conditioner rolls, the crop material mat directed toward the rolls will be arranged in several smaller windrow-like streams of crop. Conventional conditioner rolls having a single chevron, spiral roll, or similar large scale tread patterns do not laterally disperse the crop mat to a significant degree to overcome the bunched crop streams inherent with a disc cutterbar. This results in discharge of a windrow of non-uniform mat thickness which is less than ideal for crop drying.
It would be advantageous to have a conditioner roll tread pattern with a repeating pattern coordinated with the position of the converged crop discharges from a rotary disc cutterbar that would laterally disperse the crop mat discharged from the cutterbar leaving a crop mat having a more uniform thickness in the resultant windrow. Further advantages would be realized by a conditioner roll tread pattern design that balances lateral dispersion of crop incoming material thereby minimizing thrust loads imposes on the roll bearings and the tendency for crop material to be concentrated at the outboard ends of the rolls and restricted by the header side walls side.